Power Control for Grid-Connected Converter to Comply With Safety Operation Limits During Grid Faults

This paper presents a new power control strategy for the grid-connected converter under grid faults. Positiveand negative-sequence reactive powers are controlled separately to effectively support the unbalanced grid voltages. Both maximum phase current limit and maximum active power oscillation limit are considered to make sure that the converter operates safely under grid faults. The spare capacity is fully used to generate active power. Simulation and experimental results are presented to demonstrate that the reactive power is generated immediately and a gradual generation of active power reduces the load of crowbar or other energy transfer devices.